The present disclosure relates to a coordinate measuring machine, and more particularly to a portable articulated arm coordinate measuring machine having targeted area illumination features integrated into the probe end of the portable coordinate measuring machine.
Portable articulated arm coordinate measuring machines (AACMMs) have found widespread use in the manufacturing or production of parts where there is a need to rapidly and accurately verify the dimensions of the part during various stages of the manufacturing or production (e.g., machining) of the part. Portable AACMMs represent a vast improvement over known stationary or fixed, cost-intensive and relatively difficult to use measurement installations, particularly in the amount of time it takes to perform dimensional measurements of relatively complex parts. Typically, a user of a portable AACMM simply guides a probe along the surface of the part or object to be measured. The measurement data are then recorded and provided to the user. In some cases, the data are provided to the user in visual form, for example, three-dimensional (3-D) form on a computer screen. In other cases, the data are provided to the user in numeric form, for example when measuring the diameter of a hole, the text “Diameter=1.0034” is displayed on a computer screen.
An example of a prior art AACMM is disclosed in commonly assigned U.S. Pat. No. 5,402,582 ('582), which is incorporated herein by reference in its entirety. The '582 patent discloses a 3-D measuring system comprised of a manually-operated AACMM having a support base on one end and a measurement probe at the other end. Commonly assigned U.S. Pat. No. 5,611,147 ('147), which is incorporated herein by reference in its entirety, discloses a similar AACMM. In the '147 patent, the AACMM includes a number of features including an additional rotational axis at the probe end, thereby providing for an arm with either a two-two-two or a two-two-three axis configuration (the latter case being a seven axis arm).
When manipulating a probe at the end of an AACMM, it is often desirable for the operator of the AACMM to work or see within part of a cavity, underneath a lip on a part for example. These or other relatively difficult to access positions often result in the surface of the part being in a shadow. It should be appreciated that this positioning sometimes makes it relatively difficult for the operator of the AACMM to properly discern features of the part being accessed by the probe for measurement. Oftentimes supplemental illumination apart from the arm of the AACMM is provided in the form of portable work lights, head mounted lights, or a hand-held light. However, these can be cumbersome for the operator of the AACMM to use, and may require additional time or manpower to set up and operate.
While existing AACMM's are suitable for their intended purposes, what is needed is a portable AACMM that has certain features of embodiments of the present invention. In particular, what is needed is an effective solution for the illumination of relatively difficult to illuminate part locations through use of targeted area illumination.